The St. Paul Planning Commission on Friday unanimously approved Ford Motor Company's plan to tear down its assembly plant in the Highland Park neighborhood, paving the way for demolition to begin this spring.

Without comment, the board ratified the zoning committee's recommendation last week to approve, with conditions, Ford's proposal to raze the plant, a project expected to take at least three years.

The conditions include restricting work to business hours during the week, control of the noise and dust created by on-site concrete crushing, and providing a Ford representative to take questions and complaints from the public.

Any appeals from the Planning Commission's decision would go to the St. Paul City Council for consideration.

According to Ford's timetable, the job of tearing down buildings will begin in May. Ford officials have warned that the unearthing of "major pollution" could slow progress of the demolition.

Ford, which closed the plant last year, wants to prepare the site for marketing to developers. The company will clean the plant to industrial standards, although city officials envision a mixed-use development on the 122-acre site that includes housing and businesses.

The plant includes two major structures, including the main assembly building dating from the 1920s and the paint building, as well as a training center built with state money in 1999.

Most of the work would be done by the end of 2015, although Ford asked that the timeline for finishing the removal of parking lots be pushed back until summer 2019.

The demolition plan had won conditional approval from the Capitol Region Watershed District and the Highland District Council.

Environmental and conservation groups urge Gov. Mark Dayton to use his line-item veto power to cancel $98 million in projects funded by what they consider an improper raid on a trust fund that depends on state lottery proceeds.